There are many fields where there is a need for the delivery of a fluid or vapor to an animal. Two important applications are in veterinary procedures, and research settings. Often in research, for example, it would be beneficial to sedate multiple laboratory animals at once; this is especially true in the field of preclinical optical imaging where a control cohort is compared to an experimental cohort. This multiple animal sedation is currently achieved in a number of ways, most commonly focusing on the delivery of the gaseous anesthetic to the nose or mouth of the lab animals through a bulky deployment chamber and individual nose-cones. A pump forces an anesthetic from a source to the inlet of a manifold. The inlet leads to a chamber with several outlets which can be fitted with external nose-cones. The laboratory animals are positioned with their noses propped in these cones so that as they breathe, they inhale the anesthetic gas.
The fluid or vapors inevitably escape from the nose-cones, and leak into the atmosphere, which poses health concerns for those working with these systems and the environment. Currently, several methods exist for reducing or eliminating the escape of gases from these apparatuses. One method involves completely enclosing the laboratory animals in an air-tight chamber attached to a vacuum line and gas trap; but this design requires more space, is more traumatic for the animals, and can limit the techniques which can be used to image the enclosed animal. A second method involves scavenging fluid after it has escaped the subject interface, such as by positioning inlets exterior to the outermost lip of the nose-cones. These inlets are routed to a vacuum line and gas trap and thus scavenge a portion of the excess gas that has diffused outside the subject interface.